Effects of Sugars and Degradation Products Derived from Lignocellulosic Biomass on Maleic Acid Production

In this study, maleic acid was produced from xylose contained in a hydrolysate generated by oxalic acid pretreatment of yellow poplar (Liriodendron tulipifera), and the factors that influenced maleic acid production were evaluated. Furfural was obtained from the hydrolysate using H2SO4 as a catalyst, depending on combined severity factors (CSFs). Furfural production increased as the H2SO4 concentration increased. Furfural yield (46.70%), xylose conversion (70.95%), and xylo-oligomer conversion (75.47%) from the hydrolysate were high at CSF 1.92 with 1.64% H2SO4. However, the furfural concentration was slightly increased at 1.64% H2SO4 to 7.10 g/L at CSF 1.89, compared with that at CSF 1.92. Maleic acid was produced from the hydrolysate (CSF 1.92 and 1.64% H2SO4) at a yield of 91.44%. Maleic acid production was slightly better when formic acid and acetic acid were included in the hydrolysate than when furfural was included alone (79.94% vs. 78.82%). Based on the results, the xylose obtained from yellow poplar can be proposed as a new substitute for fossil fuel-derived raw materials.